I've been doing BJJ for a couple months now, and always notice after class that my knees are sore, generally on the inside. Sunday after BJJ i got home and sat aronud for a couple hours after training (was totally gassed) and my knee started to get sore, fast forward 2 days and i can hardly walk, putting weight on my knee is fine but any lateral movement or bending of the knee or straightening hurts on the inside of my left knee.

I'm not too worried about the current injury because it came on fairly slowly and nothing "popped" and there was no significant event when rolling... so im fairly certain that it's just bruising because i seem to have weak knees.

I've introduced squats into my weights routine to strengthen my knees but im thinking about getting some knee compression sleeves to try and support them a bit more until they are stronger.

Is there any difference between an open patella and closed patella? From what i can gather closed patella is better for lifting because of the constant support, whilst open patella is better for flexibility and doesnt hold the patella in incorrect positions when the knee moves around. I asked my instructor (who uses closed patella sleeves) and he didn't know if there would be a difference.

If anyone knows what the main differences are between the two, or have used the shock doctor sleeves before any input would be greatly appreciated!

Personally, I found wearing a knee sleeve did very little in general. I suggest wearing proper knee pads during BJJ (either volleyball style or actual BJJ/martial arts ones) and making sure your knees are nice and warm before you start training.

Also, take lots of fish oil and ice your knees if they are sore. Also, if you can hardly walk go to a doctor or at least take some time off.

Just looking at the closed patella sleeves, it looks like there is a seam across the front of the knee. I'd imagine that could rub and irritate the knee (even if there is a backing over it), which would annoy me.

Do you think they'd provide as much support as the shock doctor ones? My knees don't tend to get irritated by the mat or anything so the only reason i want knee pads is for a bit more support.. I'm not entirely sure how i hurt my knee but if i can prevent it by adding some support it would be great

As far as exercises you can do to strengthen your knees, traditional squatting is good, but unilateral work is better. Bulgarian split squats and lunges with help your knees get stronger, so long as you do them with correct form.